1. Technical Field
The invention relates to the streaming of computer program object code across a network in a computer environment. More particularly, the invention relates to the caching of streaming applications across a computer network for faster response times to client system requests.
2. Description of the Prior Art
Retail sales models of computer application programs are fairly straight forward. The consumer either purchases the application program from a retailer that is either a brick and mortar or an ecommerce entity. The product is delivered to the consumer in a shrink-wrap form.
The consumer installs the program from a floppy disk or a CD-ROM included in the packaging. A serial number is generally provided that must be entered at installation or the first time the program is run. Other approaches require that the CD-ROM be present whenever the program is run. However, CD-ROMs are easily copied using common CDR technology.
Another approach is for the consumer to effectuate the purchase through an ecommerce entity. The application program is downloaded in its entirety to the consumer across the Internet. The consumer is emailed a serial number that is required to run the program. The consumer enters the serial number at the time the program is installed or the first time the program is run.
Once the application program is installed on a machine, it resides on the machine, occupying precious hard disk space, until it is physically removed. The installer portion of the program can also be installed on a server along with the installation files. Users within an intranet can install the program from the server, across the network, onto their machines. The program is a full installation of the program and resides on the user's machine until it is manually removed.
Trial versions of programs are also available online that are a partial or full installation of the application program. The program executes normally for a preset time period. At the end of the time period, the consumer is told that he must purchase the program and execution is terminated. The drawback to this approach is that there is an easy way for the consumer to fool the program. The consumer simply uninstalls the program and then reinstalls it, thereby restarting the time period.
Additionally, piracy problems arise once the application program is resident on the consumer's computer. Serial numbers for programs are easily obtained across the Internet. Software companies lose billions of dollars a year in revenue because of this type of piracy.
The above approaches fail to adequately protect software companies' revenue stream. These approaches also require the consumer to install a program that resides indefinitely on the consumer's hard disk, occupying valuable space even though the consumer may use the program infrequently.
The enterprise arena allows Application Service Providers (ASP) to provide browser-based implementations such as Tarantella offered by Santa Cruz Operation, Inc. in Santa Cruz, Calif. and Metaframe offered by Citrix Systems Inc. of Fort Lauderdale, Fla. A remote application portal site allows the user to click on an application in his browser to execute the application. The application runs on the portal site and GUI interfaces such as display, keystrokes and mouse clicks are transferred over the wire. The access to the program is password protected. This approach allows the provider to create an audit trail and to track the use of an application program.
AppStream Inc. of Palo Alto, Calif. uses Java code streamlets to provide streaming applications to the user. The system partitions a Web application program into Java streamlets. Java streamlets are then streamed to the user's computer on an as-needed basis. The application runs on the user's computer, but is accessed through the user's network browser.
The drawback to the browser-based approaches is that the user is forced to work within his network browser, thereby adding another layer of complexity. The browser or Java program manages the application program's run-time environment. The user loses the experience that the software manufacturer had originally intended for its product including features such as application invocation based on file extension associations.
It would be advantageous to provide a network caching system for streamed applications that allows client systems to reduce the load of streamed application servers by requesting files from other sources. It would further be advantageous to provide a network caching system for streamed applications that provides an efficient file delivery system that improves the response time for file requests.